The present invention relates to a novel method for compatibilizing, i.e. improving miscibility of, otherwise immiscible organic materials highly useful in, for example, the fibers industry, as well as the compatibilized product of the method. These compatibilized products are stable in the liquid phase at temperatures ranging from about 40° C. to about 200° C., more specifically from about 50° C. to about 100° C., depending on the phase separation transition and decomposition temperatures of the individual components of the compatibilized product. The method involves use of a glycol derived from polymerization of alkylene oxide and tetrahydrofuran (THF), the alkylene oxide having from 2 to 4 carbon atoms, i.e., poly(tetramethylene-co-alkyleneether) glycol, especially such a copolymer specially manufactured as herein described. The glycol derived from polymerization of alkylene oxide and THF may be referred to herein as an alkylene oxide copolymer. Non-limiting examples of such alkylene oxide copolymers for use herein include the poly(tetramethylene-co-alkyleneether) glycols derived from one alkylene oxide, e.g. ethylene oxide (EO), molecule and two THF molecules; one alkylene oxide, e.g. EO, molecule and three THF molecules, etc.
Mixtures of short chain glycols with long chain polyols, and polyethers with polyesters, normally immiscible or rapidly losing miscibility at temperatures within the range of from about 40° C. to about 100° C. have a variety of important commercial uses. For example, ethylene glycol (EG) and butanediol (BDO) are generally immiscible with polyether polyols such as polytetramethylene ether glycol (PTMEG) at these temperatures. Such mixtures are important commercially for the preparation of polyurethane elastomers, coatings and adhesives by the reaction of this mixture with one or more diisocyanates and assorted additives. Further, polyethylene glycol (PEG) and polypropylene glycol (PPG) are generally immiscible with polyether polyols such as polytetramethylene ether glycol (PTMEG) at these temperatures. These later mixtures are important commercially for the preparation of moisture permeable or absorbent articles. Mixtures of polyethers such as PTMEG and polypropylene glycol (PPG) with polyesters such as polycaprolactone glycol (PCLG) are generally immiscible at these temperatures and they are commercially useful for making a broad range of elastomers and coatings requiring ether and ester properties.
Due to the importance of these compounds being compatible in mixture at temperatures within the range of from about 40° C. to about 100° C. or higher, researchers have tried to effect compatibility by a variety of different methods. For example, techniques have been described for solubilizing some of these mixtures for commercial applications, but they have troublesome shortcomings or deficiencies which create processing and handling problems which add to costs for production of, for example, polyurethane elastomers, coatings, adhesives and foams.
U.S. Pat. No. 4,226,756 describes compositions of polyols and ethylene glycol in which the polyol contains internal oxyethylene and oxypropylene groups and additional oxyethylene end groups. These compositions are limited to polyols with a polyoxypropylene polyoxyethylene glycol structure. Additionally, the balance of oxyethylene internal and end groups is an important variable in the function of the materials as compatibilizers.
U.S. Pat. No. 4,385,133 describes a process for the preparation of polyurethane in which a low molecular weight glycol is rendered miscible in a polyol mixture by employing two polyoxypropylene polyoxyethylene polyols of varying molecular weight and ethylene oxide (EO) content. This process requires the presence of two polyoxypropylene polyoxyethylene glycols of different molecular weights and oxyethylene content.
U.S. Pat. No. 6,063,308 details a process for making a homogeneous mixture of curative, polyol, and other materials by allowing the mixture to react with a small amount of a diisocyanate and a 2° or 3° amine. This process is of limited utility because the components must undergo a chemical reaction in order to become homogeneous and requires intensive mixing. It is likely that the desired reaction product is also of a higher viscosity than the starting materials, and is not described or characterized.
U.S. Pat. No. 6,093,342 teaches a variation of the process of above U.S. Pat. No. 6,063,308 in which two immiscible high molecular polyols and optionally a low molecular weight glycol are compatibilized by allowing the mixture to react with a small amount of a diisocyanate and a 2° or 3° amine. This process also requires intensive mixing so that the materials can react chemically. The uncharacterized composition product of this reference must be higher in viscosity than the starting materials, and is not described or characterized. Processes for homogenizing mixtures of polyether and polyester are also described.
The techniques of the above patent references have serious commercial limitations in that they are restricted to a particular class of polyols (polyoxypropylene polyoxyethylene polyols) or they entail the use of reactive components and efficient mixing of the incompatible components which is complicated and nontrivial on a large commercial scale. None of these references teach or suggest a method for preparing a compatibilized mixture of otherwise immiscible organic materials stable in the liquid phase at temperatures ranging from about 40° C. to about 200° C., more specifically from about 50° C. to about 100° C., depending on the phase separation transition and decomposition temperatures of the components of the compatibilized product, or the compatibilized composition comprising a glycol derived from polymerization of alkylene oxide and tetrahydrofuran (THF), the alkylene oxide having from 2 to 4 carbon atoms, i.e. poly(tetramethylene-co-alkyleneether) glycols. These compatibilized compositions have the unique combination of properties disclosed herein, such as, by way of non-limiting examples, remaining homogeneous in the temperature range of from about 40° C. to about 200° C., more specifically from about 50° C. to about 100° C., so that they are easy to handle in a commercial environment and can be used without agitation. These compositions can produce polymers with properties comparable to those made from difficult to handle, incompatible components.